The harsh reality is that most companies will not allow an individual without a type of contractor license and more importantly insurance / bonding onto their roof, let alone an individual roping items over the edge. Most locations would likely require an experienced team with coverage for damage and injury.
Often the least expensive route is to hire a boom to lift the dish and mount to the ground (or onto a flatbed and dissasemble off of the company premises). I have arranged installation and removal of satellite gear on many multiple story buildings. Each is unique in the requirements, except for the universal "don't damage my roof and may we have a copy of your insurance binder/bonding).
Often the least expensive route is to hire a boom to lift the dish and mount to the ground (or onto a flatbed and dissasemble off of the company premises). I have arranged installation and removal of satellite gear on many multiple story buildings. Each is unique in the requirements, except for the universal "don't damage my roof and may we have a copy of your insurance binder/bonding).